Very stable excimer or molecular fluorine laser

US6243405A · kind A · utility

Assignee

• Lambda Physik AG · DE

Inventors

• Stefan Borneis · Fulda, DE
• Klaus Brunwinkel · Göttingen, DE
• Uwe Stamm · Göttingen, DE
• Frank Voss · Berlin, DE

Key dates

• Filing date: Jan 18, 2000
• Grant date: Jun 5, 2001
• Expiry date: Jan 18, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/134
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A technique of stabalizing during operation a gas mixture with a gas composition initially provided within a discharge chamber of an excimer or molecular fluorine gas discharge laser includes monitoring a temporal pulse shape of the laser beam and adjusting and/or determining the status of the gas mixture based on the monitored temporal pulse shape. The monitored temporal pulse shape is preferably compared with a reference temporal pulse shape. The difference or deviation between the monitored temporal pulse shape and a reference temporal pulse shape is calculated. The amount of and intervals between gas replenishment actions are determined based on the calculated deviation. The energy of the beam is also monitored and the driving voltage and gas actions are adjusted to stabilize the energy, energy stability and/or energy dose.